Further clarification is being sought of the relationship between experimental diabetes mellitus in the rat (streptozotocin, 80 mg/kilo), and the net biosynthesis of plasma glycoproteins by the isolated perfused liver from these rats at 2 to 52 weeks after the onset of diabetes. Measurements with specific antisera by single radial diffusion or electroimmunodiffusion are being made to evaluate effects of diabetes (with or without insulin treatment) on net hepatic synthesis of albumin, fibrinogen, alpha-1 acid glycoprotein, alpha-1-macro-globulin, haptoglobin, hemopexin, C-3 component of complement, and antithrombin-III. Correlations between changes in plasma glycoproteins and renal pathology will be looked for.